<template>
  <div>
    <h1>当前求和为:{{sum}}</h1>
    <h3>当前放大十倍后:{{bigSum}}</h3>
    <h3>我在{{school}},学习{{subject}}</h3>
    <select v-model.number="n">
      <option value="1">1</option>
      <option value="2">2</option>
      <option value="3">3</option>
    </select>
    <button @click="increment">+</button>
    <button @click="decrement">-</button>
    <button @click="decrementOdd">当前求和为奇数再加</button>
    <button @click="decrementWait">等一等再加</button>
  </div>
</template>

<script>
import { mapState, mapGetters } from 'vuex'
export default {
  name: 'Count',
  data () {
    return {
      n: 1,//用户选择的数字
    }
  },
  methods: {
    increment () {
      this.$store.commit('JIA', this.n)
    },
    decrement () {
      this.$store.commit('JIAN', this.n)
    },
    decrementOdd () {
      this.$store.dispatch('jiaOdd', this.n)
    },
    decrementWait () {
      this.$store.dispatch('jiaWait', this.n)
    }
  },
  computed: {
    //靠程序员自己去写计算属性
    /* sum () {
      return this.$store.state.sum
    },
    school () {
      return this.$store.state.school
    },
    subject () {
      return this.$store.state.subject
    }, */
    //借助mapState生成计算属性,从state中读取数据(对象写法)
    //...mapState({ he: 'sum', xuexiao: 'school', xueke: 'subject' }),

    //借助mapState生成计算属性,从state中读取数据(数组写法)
    ...mapState(['sum', 'school', 'subject']),

    /* ********************************************************* */
    /* bigSum () {
      return this.$store.getters.bigSum
    }, */

    //借助mapGetters生成计算属性,从getters中读取数据(对象写法)
    //...mapGetters({bigSum:'bigSum'})

    //借助mapGetters生成计算属性,从getters中读取数据(数组写法)
    ...mapGetters(['bigSum'])
  },
  mounted () {

  },
}
</script>

<style scoped>
button {
  margin-left: 5px;
}
</style>